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| author | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2009-01-06 14:55:50 +0000 |
|---|---|---|
| committer | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2009-01-06 14:55:50 +0000 |
| commit | 17409471b5384d8e4e5ec3228672ce2fbcabff43 (patch) | |
| tree | c0105e306cb047f735ee62e610adea8e67e2e98c | |
| parent | e4dcb11ead8f4109f2b97aaef93807f1fcba818f (diff) | |
| download | postgresql-17409471b5384d8e4e5ec3228672ce2fbcabff43.tar.gz postgresql-17409471b5384d8e4e5ec3228672ce2fbcabff43.zip | |
Fix logic in lazy vacuum to decide if it's worth trying to truncate the heap.
If the table was smaller than REL_TRUNCATE_FRACTION (= 16) pages, we always
tried to acquire AccessExclusiveLock on it even if there was no empty pages
at the end.
Report by Simon Riggs. Back-patch all the way to 7.4.
| -rw-r--r-- | src/backend/commands/vacuumlazy.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c index c4bf719ceba..d0010d336c0 100644 --- a/src/backend/commands/vacuumlazy.c +++ b/src/backend/commands/vacuumlazy.c @@ -38,7 +38,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.81.2.4 2007/09/24 03:53:02 alvherre Exp $ + * $PostgreSQL: pgsql/src/backend/commands/vacuumlazy.c,v 1.81.2.5 2009/01/06 14:55:50 heikki Exp $ * *------------------------------------------------------------------------- */ @@ -181,8 +181,9 @@ lazy_vacuum_rel(Relation onerel, VacuumStmt *vacstmt) * number of pages. Otherwise, the time taken isn't worth it. */ possibly_freeable = vacrelstats->rel_pages - vacrelstats->nonempty_pages; - if (possibly_freeable >= REL_TRUNCATE_MINIMUM || - possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION) + if (possibly_freeable > 0 && + (possibly_freeable >= REL_TRUNCATE_MINIMUM || + possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION)) lazy_truncate_heap(onerel, vacrelstats); /* Update shared free space map with final free space info */ |